Ab initio calculations have been carried out at the Hartree-Fock and the second order Moller-Plesset perturbation theory MP2 levels using 6-31G^*^* basis set to determine the molecular energies, dipole moments, atomic charges and electrostatic potential distributions of DNA bases, adenine, cytosine, guanine and thymine. The electron correlation is included in the wave functions at the MP2 level using the Z-vector method. The atomic charges were obtained by the Mulliken population analysis, Breneman's electrostatic potential derived atomic charges CHELPG model and Reed-Weinhold's natural population analysis NPA. Based on these results, the effect of elecetron correlation of the DNA bases were systematically analysed in this article.

Key words: THYMINE, GUANINE, ELECTRONIC STRUCTURE, AB INITIO CALCULATION, CYTOSINE, ADENINE, ELECTRON CORRELATION